Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate idempotent, non-destructive, not read-only. The description adds valuable behavioral context: the token's persistence (permanent if added to config, session-only if pasted) and the two-step flow (browser login → copy token). This goes beyond the structured annotations without contradicting them.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no fluff. The first sentence states the core action, the second provides the best-practice and alternative. All information is essential and front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with one optional parameter, no output schema, and clear annotations, the description covers all necessary details: the login flow, token usage, persistence, and invocation patterns. Nothing essential is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has zero description coverage, but the description fully explains the 'token' parameter: it's a JWT pasted by the user, and it clarifies that calling with no args returns a login link. This compensates entirely for the missing schema documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action: logging in to the MCP.AI server via browser and token. It specifies two distinct modes (permanent via config header, session-only via token argument), which sharply distinguishes it from sibling tools like 'connect' or 'marketplace'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit instructions for when to use the tool (to authenticate) and how to use it (either pasting a token or calling with no args to get a link). It also contrasts permanent vs session login, offering alternatives for token handling. However, it doesn't explicitly state when not to use this tool, though that's implicitly obvious.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.